Shoe filler



H. S. MILLER Oct. 24, 1933.,

SHOE FILLER Filed March 28, 1930 lzw/ jam/daf 7?,

vPatented @ein 2431,. i933 UNITED STATES' www@ PATENT ottica SHOE FILLER Application March 2s, 1930. serial No. 439,714

3 claims'.

This inventionl relates to compositions more particularly intended for lling shoek bottoms and to the method of applying or using them in shoes of various types. In the manufacture of shoes 5 such as welt, McKay, Littleway, and Compo, the cavity in the bottom of the shoe is lled with a suitable composition 'before xing the outer sole in place. Heretofore it has been common practice to use so-called hot llers, which consist of mixtures of granulated cork and a petroleum binder such as Wax tailings. These fillers are heated and spread in hot, plastic condition in the cavity and then permitted to set. Such llers are faulty, in that they have insuflicient body and strength to withstand the continued stresses of Wear in a shoe, with the result that, instead of lying as a smooth sheet in the shoe, they crumble and gather in bunches at the toe and arch portions, where the pressure of the foot is smallest, and fail to give adequate support to the ball portion of the foot. So-called tar paper has sometimes been used as a shoe bottom ller, but it is not waterproof; it does not flow or yield sumciently under the Happlication of heat to ll the shoe bottom completely; and under the friction of wear it disintegrates to form wads or lumps which accumulate as does thehot filler. Leather is sometimes used'to ll shoe bottoms, and while suiciently strong and tough td withstand Wear, is nevertheless undesirable, in that it is expensive;

` it cannot be made to ll the cavity completely;

and it is not Waterproof. In accordance with the present invention, I produce a -shoe filler composition, preferably in pre-fabricated sheet form of substantially uniform thickness, comprising a' uniform mixture of asuitable thermoplastic material, viibrous material of sufficiently long iiber length to be'feltable, and rubber, the thermoplastic material being present in suflicient amount to permit the plasticization of the composition -by heat. The brous material may, for example, be that derived from a felted structure without substantial impairment of the bers, as hereinafter described. The iibrous component is not only advantageous as a bulk material, but serves to impart strength to the composition and renders the composition resistant tomovement or displacementin the shoe. The rubber imparts resiliency, exibility,

50 waterproof and wear-resisting qualities to the composition. One of the desiderata possessed by the composition is that it does not squeeze out from under the ball portion of the foot, where maximum pressure is exerted, to other parts of the shoe. When used in sheet form, it possesses the advantage that blanksshaped for insertion in shoe bottoms may be cut therefrom and then l subjected to heat, under the action of which they become plastic and more-or less tacky, so that they may be applied directly to the shoe bottom and fixed in place. The clearance or space between the bottom seam and the edge of the composition blank may then be lled and sealed to render the bottomV completely waterproof, by compressing the blank immediately after fixing to the shoe bottom, as against a hot roll.

While it is possible to start with raw ber inv bulk condition, thermoplasticvmaterial, and rubber, in producing the composition of the present invention,4 nevertheless an attractive and inexpensive source of raw material is box toe scrap or Waste produced in the manufacture of socalled thermoplastic box toe blanks. Such scrap comprises a i'lbrous foundation or felt, which is impregnated with thermoplastic materials such as rosin,Montan wax, and asphalt, the fibrous material and thermoplastic material being present in the relative proportions desired in the composition of the present invention, and it may y or may not contain rubber. The scrap may 80 be readily disintegrated under the application of heat, whereupon rubber may be added thereto in the desired amount to produce thenished composition of the present invention; and the com'- position may then be formed into sheets.

A specific example of procedure falling within the purview of the present invention and yielding a composition having the desired characteristics was carried out as follows. Four hundred parts by weight of thermoplastic box toe scrap, consisting of 100 parts of felt and 300 parts of thermoplastic material, was placed in a jacketed Werner and Peiderer mixer, and the mixer was s et'in operation with steam under 15 pounds gage l'pressure passing through the jacket. About 10 95 l parts of Water was added to the mixer to promote the conduction of'heat through the mass. Under the action of the heat and the pulling and stretching, the felted structure of the scrap was destroyed, but without impairing the fibers, so that after about thirty minutes a uniformly smooth and plastic mass was obtained. To this hot mass was then added 100 parts of rubber which had previously undergone plasticization on a rubber 105 compounding roll. After about fifteen minutes y working of the mixer, the rubber was uniformly dispersed into the hot mass, whereupon the resulting uniform composition was formed into a sheet of substantially uniform thickness by rolling out between cold rolls, such as are commonly used in linoleum manufacture.

In producing a composition such as described, any suitable rubber or rubber compound may be used, reclaimed rubbers serving as well as crude rubbers. If desired, concentrated aqueous rubber dispersions of natural or artificial variety may be used, in which case mixing of the rubber with the other materials of the composition is facilitated, but, inasmuch as dispersions are comparatively expensive, their use is generally not preferred. The finished composition may be rolled out into sheets of various thicknesses, for instance from .035 to .120 inches, or greater, depending upon the depth of cavity in the type of shoe in which it is to be used. As already indicated, the fibrous constituent imparts strength to the composition so that such comparatively thin sheets do not tend to disintegrate when handled or put to work in a shoe bottom. Thus, welt shoes have cavities considerably deeper than those of other types of shoes in which the depth of cavity is determined by 'the thickness of the upper leather.

On the accompanying drawing, which illustrates the manner of applying or using the sheeted composition in shoes,

Figure l is a fragmentary perspective of the sheeted composition, showing shoe filler blanks cut therefrom.

Figure 2 illustrates the heating of a blank before its insertion in a shoe bottom.

Figure 3 is a plan View of a welt shoe in the process of manufacture, with the shoe filler blank applied thereto.

Figure 4 represents a greatly enlarged fragmentary section through the shoe on line 4 4 of Figure 3.

Figure 5 illustrates the manner of sealing the cavity of the shoe.

Figure 6 represents a longitudinal section through the toe portion of the finished shoe.

After shoe bottom filler blanks have been died out or cut from the sheeted composition 1 of the present invention, as shown in Figure 1, they are subjected to sufficient heat to become plastic and sticky. To this end, a pre-fabricated blank 2 of substantially uniform thickness may be placed on a hot plate 3, as shown in Figure 2, and allowed to remain thereon until it is uniformly heated to a temperaturegof about 200 F., at which temperature it is plastic and sticky. The blank so conditioned is then applied to the bottom of a shoe, which, as shown in Figure 3, may be a weltshoe, whose inner sole 4 receives the blank. The blank is preferably of sufficient thickness to project slightly above the channel rib 5 of the shoe, and is of a shape corresponding to the cavity of the shoe, but, as shown in Figure 4, its size is preferably such that there the channel rib 5 so that the blank may be applied to the inner sole without forcing it by the rib. Immediately after the application of the blank to the shoe bottom and while the blank is still in plastic condition, the shoe is pressed in contact with a hot roll 7, as shown in Figure 5, under the action of which the blank is squeezed out to fill completely the cavity, as best shown in Figure 5. At the end of this operation, the

.filler blank 2 is spread or expandedinto sealing 85 contact with the channel rib 5, and lies practically ush with the upper edge 5a of the rib. An outer sole 8 may then be stitched to the welt 9 of the shoe, the filler lying in between the inner and outer soles, as ordinarily.

The use of a shoe-filler blank of the composition hereinbefore described makes possible noteworthy economies in the manufacture of shoes, as comparatively little labor or skill is required in applying the pre-fabricated blank of substantially uniform thickness to the shoe bottom and then rolling it out to complete the filling of the cavity. The shoe manufacturer may be supplied with the composition in sheet form and proceed to cut or die out the blanks, or the blanks may be furnished to him by the manufacturer of the composition ready for heating and assembly with shoes.

I claim:

1. A shoe bottom ller, comprising a blank of sheet material of substantially uniform thickness pre-fabricated and shaped for insertion in the shoe bottom, comprising a mixture of thermoplastic material, fibrous material of sumciently long ber length to be feltable, and rubber, said blank containing sufficient thermoplastic material to become plastic and sticky at a temperature of about 200 F.

2. A shoe bottom ller, comprising a blank of sheet material of substantially uniform thickness pre-fabricated and shaped for insertion in the shoe bottom, comprising by weight a mixture of about 300 parts of thermoplastic material, 100 parts of fibrous material of sufficiently long fiber length to befeltable, and 100 parts of rubber, said 120 blank being characterized by its tendency to become plastic and sticky at a temperature of about 200 F.

3. A shoe bottom ller, comprising a blank of sheet material pre-fabricated and shaped for insertion in the shoe bottom, comprising a mixture of thermoplastic material, fibrous vmaterial of suiciently long fiber length to be feltable, and rubber, said blank containing sufficient thermoy plastic material to become plastic and sticky at y.thickness of about .035 to .120 inches. is sufficient clearance 6 Abetween the blank and IIAROLD S. MILLER. 

